<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Reference</title>
<style>
.clamp {
  display: flow-root;
  font: 16px / 32px serif;
  white-space: pre;
  background-color: yellow;
}
.clamp > div {
  padding: 2px;
  border: 2px solid black;
}
</style>
<div class="clamp"><div>Line 1
Line 2
Line 3
Line 4…</div></div>
